Computer simulations such as SPICE or behavioral modeling analysis require component or device models, with device characterizations performed in both frequency domain and time domain. However, it is well known that a SPICE level model contains such detail that it is impractical to use such a model to simulate complex circuits as it takes too much computer time or memory, or both. Device models may be based on data sheet parameters which can differ from parameters of actual physical components, resulting in inaccurate characterizations.
Characterizations of components, circuits and systems are needed in order to model an electronic design. Several conventional approaches have been taken to characterization. Equipment such as oscilloscopes, LCR bridges, network analyzers, and frequency spectrum analyzers are typically used. Typically, a component's impedance may be characterized or tested at a given frequency, such as with an LCR bridge. Oscilloscope measurements of electrical response with respect to time are utilized in combination with swept frequency sources to obtain a wide range of responses over several decades of frequency. However, while conventional time domain instruments such as oscilloscopes will provide time response parameters such as rise and fall time, delay time, etc., these parameters are not sufficient to describe the system or circuit behavioral characteristics necessary for simulation or mathematical system analysis.
A second approach to characterization using network analyzers to provide frequency information and extracting parameters for simulations can only be applied in the linear region of operation, and therefore cannot simulate non-linear or switching circuits.
Another approach employs predefined models of component behavior, with adjustments made to model parameters until the model response matches the actual device response. While a certain set of parameters may adequately approximate a portion of the actual response, the approach has drawbacks in that a set of parameters providing a good match over one portion of the device response curve may result in a poor match of behavior over other portions of the device response curve. It therefore becomes necessary to determine multiple sets of model parameters to adequately cover an entire response curve.
Electronic circuits, mechanical and electro-mechanical components and physical device characteristics may be described by mathematical expressions such as Laplace transform notation. In such case, the characteristics may be described as a magnitude factor and Laplace domain response parameters such as poles and zeros.
There is the need for a system that will characterize components, circuits and systems and extract the root parameters necessary for modeling, and will confirm the suitability of the model by comparing the results of the model using the extracted parameters and the physical system measurements.